Theresa May has done a great job at playing for time in the last year, but sooner or later she'll have to betray someone.

All of her decisions, and her decision-making process, have been influenced by her primary concern: placating her own cabinet in order to stave off a heave.

Mrs May has done a remarkable job of publicly maintaining that the British government's aspiration for Brexit - leave the customs union and single market, establish new trade agreements world-wide, and protect the status quo in Northern Ireland - is realistic.

Instead of admitting that these conflicting objectives are simply irreconcilable; unlike everyone else, the UK prime minister says she can deliver on all of the above.

But you have to hand it to her: it's been one year on from the beginning of the Brexit talks, and she is still in office, albeit embattled. And the EU and Ireland are still open to and willing to engage in whatever ingenious proposals lie ahead. Sources from both Dublin and the Tory party say everything she does is to manage her domestic situation, and where she is torn between dealing with the reality of Brexit, and trying to create unity with ideologues in her cabinet like Liam Fox, Boris Johnson, and Michael Gove.

Aside from the fact that the situation is unsustainable, it must be incredibly stressful, and not to mention humiliating. Only two weeks ago her foreign secretary penned a piece from the US where he was supposed to be leading a mission to persuade Donald Trump to stay in the Iran deal. Instead he publicly dismissed her proposals for a solution to avoiding customs checks on the Irish Border as "crazy".

Then her new appointee for home secretary, Sajid Javid votes against the same policy the first chance he gets. It shows an outstanding lack of foresight to appoint someone to replace an ally in Amber Rudd, for someone who'll stab you in the back at a time when you're in dire need.

This week, talk of a eureka moment filled the airwaves; when yet another too-good-to-be-true proposal was leaked which said that cabinet had finally agreed on the UK staying within the EU customs system until such a time as a better solution - perhaps in the form of technology - was established.

Essentially, it was a British attempt at translating their version of the "backstop" agreed in December, that would see the UK match EU tariffs after 2020 if there is no deal on their preferred customs arrangements.

Mrs May gave a "verbal", "conceptual" outline of this during a 45-minute meeting with the Taoiseach this week, in which he politely explained it was grossly inadequate. Notwithstanding the fact that detail was in short supply, and at this stage there needs to be a proposal in writing, it completely omitted a mention of how this plan would deal with EU rules and regulations on goods which might enter the single market through Northern Ireland.

Britain has been one of the most constructive members of the single market since it was introduced in 1993; it's another reason why the UK will be sorely missed. So it is not credible that her officials simply forgot that the Border issue will only partly be solved through shared customs plans. The Irish side was heartened that her direction of travel is correct, and because of this might even be willing to give her even more time.

Meanwhile, there are rumours within the Tory party that David Davis and perhaps Mr Johnson are looking for a way out.